Demountable Cable Cutter

ABSTRACT

A cable cutter ( 10 ) includes a hub ( 2 ) for attaching it to a boat&#39;s screw shaft ( 1 ) and a blade ( 3 ) carried by the hub, the cable cutter including several mutually demountable parts ( 11, 12 ) allowing the screw shaft ( 1 ) to be inserted radially into the hub ( 2 ).

The present invention relates to the nautical field, and more particularly to a cable cutter which can be mounted on a boat's propeller shaft. Such a cable cutter is useful for releasing the propeller shaft when a cable gets caught in the shaft and risks blocking the rotation of the propeller. It will be understood that the word cable used here covers a large number of objects capable of getting caught around the shaft, in particular, cables, buoy ropes, fishing net cables or parts of fishing nets, or weeds.

Such a cable cutter is disclosed by the document FR2768120. However, the mounting of such a cable cutter is carried out during dry-docking of the boat, which is expensive. It is then necessary to remove the propeller, which means using a hub extractor, and generally requires the intervention of a professional.

Moreover, certain propeller shafts are mounted on brackets. Such a bracket is attached to the hull of the boat and constitutes an intermediate support for the propeller shaft. Thus, a first part of the shaft extends from the point from where it leaves the hull to the bracket, and a second part extends from the bracket to the propeller. A cable cutter mounted on the second part, between the bracket and the propeller, as is the case with a cable cutter of the prior art, is ineffective if a cable gets caught around the first part of the propeller shaft.

The purpose of the invention is to propose a cable cutter which has improved mounting facilities and which can respond to the problem posed by propeller shafts mounted on an intermediate bracket.

According to the invention, such a cable cutter comprising a hub for attaching it to a boat's propeller shaft and a blade carried by said hub, said cable cutter comprising several mutually demountable parts so that the propeller shaft can be inserted radially into the hub.

According to a first embodiment, the several parts are two parts which can be demounted and assembled along an axial plane of the hub. They are advantageously provided in order to be held by at least one bolt arranged so that a first part comprises a housing for supporting the head of said bolt and the second part comprises a threaded zone for engaging with said bolt.

According to a second embodiment, the several parts are two parts which can be demounted and assembled along two separation planes arranged on either side of an internal bore of the hub, and defining between them an opening at least as wide as the diameter of said bore. The planes can be substantially symmetrical relative to an axial plane of the hub, Moreover they can also be parallel to each other and optionally tangent to the bore.

In this second embodiment, the parts can be provided in order to be held by at least one bolt, a first part comprising opposite each other, on either side of the opening, on the one hand a housing for supporting the head of said bolt and on the other hand a threaded zone for engaging with said bolt, the second part comprising an unthreaded hole for the passage of said bolt between the separation planes.

In order to lock the cable cutter relative to the shaft, in particular in order that there is no relative movement between them under the forces caused by cutting a cable, the cable cutter advantageously comprises a locking screw screwed into at least one of the parts, the locking screw being provided in order to exert a locking force against the shaft.

Other features and advantages of the invention will also become apparent from the description below, which relates to non-limitative examples.

In the attached drawings:

FIG. 1 is a perspective view of a first embodiment of a cable cutter according to the invention, mounted on a propeller shaft;

FIG. 2 is an exploded perspective view of the cable cutter of FIG. 1;

FIG. 3 is an exploded top view of a second embodiment of a cable cutter according to the invention; and,

FIG. 4 is a diagrammatic view of a part of a boat comprising a shaft mounted on an intermediate bracket and equipped with two cable cutters according to the first embodiment, illustrated in FIGS. 1 and 2.

FIG. 1 represents a cable cutter 10 mounted on a propeller shaft 1. The cable cutter is generally symmetrical in shape around an axis X of revolution. As more particularly illustrated in FIG. 2, it comprises two parts 11, 12 which can be separated along an axial plane P, i.e. comprising the axis of revolution X. Without the position of FIG. 1, when the cable cutter is mounted on the propeller shaft 1, the axis X merges with the axis of revolution of the propeller shaft 1.

As illustrated in FIG. 1, once assembled, the two parts form together a hub 2 provided so as to be adjusted around the propeller shaft 1 and an annular blade 3 extending radially outwards, from and around the hub 2. The blade 3 comprises a cutting outside edge which is substantially circular, extending over the whole periphery of the blade. This outside edge is constituted by teeth substantially analogous to those of a serrated knife blade.

The hub 2 comprises a bore of the cylindrical hub 5, with a diameter substantially identical to a diameter D1 of the shaft 1. The hub bore is provided for passing the shaft 1 through the cable cutter 10. The plane P cuts the hub bore diametrically, so that in each part 11, 12 of the cable cutter 10, a corresponding portion of the hub bore 5 comprises an opening with a width substantially equal to the diameter D1 of the shaft. Thus, the shaft can be inserted radially into the respective portions of the hub bore 5, so that the two parts 11, 12 can be assembled radially around the shaft. It is therefore unnecessary to remove the propeller in order to mount such a cable cutter.

Two bolts 13 allow the assembly and the holding, between them, of the two parts 11, 12. The cable cutter comprises two holes 14 for receiving the bolts 13, drilled in the hub 2, on either side of the bore 5. Each hole 14 is perpendicular to the plane P. It comprises a first wide zone 141, for receiving the head of the bolt 13; a second zone 142 with a reduced diameter extends the first in order to allow the body of the bolt to pass through. The first zone opens onto the periphery of the hub. The second zone opens onto the plane P. The first and the second zone are unthreaded. A third zone 143, threaded for engaging with the bolt 13, extends the second zone through the second part 12.

A locking screw 15 is also provided. Its purpose is to prevent the relative movement of the shaft and the cable cutter. It is screwed into a thread 16 passing through the hub 2 between its periphery and the bore 5, in the second part 12.

A second embodiment of a cable cutter according to the invention will now be described, with reference to FIG. 3. This embodiment will be described only where it differs from the embodiment described previously with reference to FIGS. 1 and 2. Similar elements are assigned the same reference numbers.

In this second embodiment, the cable cutter comprises two parts 21, 22, not symmetrical with each other. It comprises a first part 21 being “C”-shaped, and a second complementary part 22. The branches of the C are defined by two planes R parallel to each other and extending tangentially to the bore 5. A first substantially semi-cylindrical portion of the bore 5 is carried by the first part, and a second complementary portion is carried by the second part 22. The distance between the parallel planes R is substantially equal to or greater than the diameter D1 of the shaft.

A portion of the hub bore 5 carried by the first part 21 therefore comprises an opening with a width substantially equal to the diameter D1 of the shaft, this opening extending between the planes R. Thus, as illustrated in FIG. 3 by the arrows F, the shaft can be inserted transversally inside the first “C”-shaped part 21, then the second complementary part, makes the cable cutter complete again. This can be done without it being necessary to remove the propeller, as for the embodiment of FIGS. 1 and 2.

A bolt 13 allows the assembly and the holding, between them, of the parts 21, 22. A hole 14 is provided in the hub 2 for receiving the bolt 13. The hole 14 is perpendicular to the planes R. It comprises, at one end of one branch of the “C”, a first wide zone 141, —for receiving the head of the bolt 13 and a second zone 142 with a reduced diameter which extends the first in order to allow the body of the bolt to pass through. The first zone opens onto the periphery of the hub. The second zone opens onto a respective plane R. The first and the second zone are unthreaded. A third zone 144, threaded for engaging with the bolt 13, is drilled opposite the second zone through the other branch of the “C”-shape. The third zone extends between the respective plane R and periphery of the hub, of the other branch. A fourth zone 145 is drilled through the second part 22, for the adjusted passage of the body of the bolt 13, and the holding in place of this second part relative to the first.

A locking screw 15 is also provided in a thread 16 through the hub, in the first part 21.

FIG. 4 illustrates a part of a boat 30, in the vicinity of a propeller 31 of the boat 30. The boat has a hull 32. A propeller shaft 1 leaves the hull 32 through a stern post 33, and carries the propeller 31 at one end distant from the stern post 33. Given the external length of the shaft 1, a bracket 34 ensures the support of the shaft between the stern post and the propeller, a first region 36 of the shaft 10 extending between the stern post and the bracket, and a second region 37 extending beyond the bracket, to the propeller.

Thanks to the principles of the invention, two cable cutters 10 as described previously with reference to FIGS. 1 and 2. A first cable cutter 10 is mounted in the first region 36, in the vicinity of the stern post. A second cable cutter 10 is mounted in the second region 37.

Of course, the invention is not limited to the examples which have just been described, and numerous adjustments can be made to these examples without exceeding the scope of the invention.

In particular, it can be provided that the parts differ in shape and number from those of the embodiments described previously.

In the second embodiment, the planes defining the two parts need not be parallel, providing they define an opening greater than or equal to the diameter of the propeller shaft.

The planes can be also replaced by other complementary shapes, comprising for example sawteeth for the mutual fitting together of the parts of the cable cutter.

In the arrangement of FIG. 4, in order to improve the effectiveness of the system, a third cable cutter can be provided, arranged in the first region, so that there is a cable cutter on either side of the bracket. 

1. Cable cutter (10;20) comprising a hub (2) for attaching it to a propeller (31) shaft (1) of a boat (30) and a blade (3) carried by said hub, said cable cutter comprising several mutually demountable parts (11, 12;21, 22) so that the propeller shaft can be inserted radially in the hub.
 2. Cable cutter according to claim 1, characterized in that the several parts are two parts (11, 12) which can be demounted and assembled along an axial plane (P) of the hub.
 3. Cable cutter according to claim 2, characterized in that the parts are provided in order to be held by at least one bolt arranged so that a first part comprises a housing (141) for supporting the head of said bolt and the second part comprises a threaded zone (143) for engaging with said bolt.
 4. Cable cutter according to claim 1, characterized in that the several parts are two parts (11, 12) which can be demounted and assembled along two separation planes (R) arranged on either side of an internal bore (5) of the hub (2), and defining an opening at least as wide as the diameter (D1) of said bore (5).
 5. Cable cutter according to claim 4, characterized in that the planes (R) are substantially symmetrical relative to an axial plane of the hub, parallel to each other and tangent to the bore.
 6. Cable cutter according to claim 4, characterized in that the parts are provided in order to be held by at least one bolt, a first part (21) comprising opposite each other, on either side of the opening, on the one hand a housing (141, 142) for supporting the head of said bolt and on the other hand a threaded zone (144) for engaging with said bolt, the second part comprising an unthreaded hole (114) for the passage of said bolt between the separation planes (R).
 7. Cable cutter according to claim 1, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1).
 8. Cable cutter according to claim 5, characterized in that the parts are provided in order to be held by at least one bolt, a first part (21) comprising opposite each other, on either side of the opening, on the one hand a housing (141, 142) for supporting the head of said bolt and on the other hand a threaded zone (144) for engaging with said bolt, the second part comprising an unthreaded hole (114) for the passage of said bolt between the separation planes (R).
 9. Cable cutter according to claim 2, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1).
 10. Cable cutter according to claim 3, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1).
 11. Cable cutter according to claim 4, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1).
 12. Cable cutter according to claim 5, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1).
 13. Cable cutter according to claim 6, characterized in that it comprises, screwed into at least one of the parts, a locking screw on the propeller shaft (1). 